UISearchController使用

iOS8之前我们使用UISearchDisplayController做TableView的本地搜索

iOS8提供实现搜索功能的SDK：UISearchController（iOS8.0之后）、UISearchDisplayController（iOS8.0之前，iOS8.0之后不建议再使用）。

遵守UISearchResultsUpdating协议

@interface ZWRecommendationFocusViewController()<UISearchResultsUpdating>
@property (strong, nonatomic) NSArray *list;
@property (strong, nonatomic) NSMutableArray *searchList;
@property (strong, nonatomic)UISearchController *searchController;
@end

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return (!self.searchController.active)?1:1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return (!self.searchController.active)?self.list.count:self.searchList.count;
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    ZWFocusList *list=(!self.searchController.active)?self.list[indexPath.row]:self.searchList[indexPath.row];
    static NSString *identifier = @"cell";
    ZWFocusListTableViewCell *cell = [ZWFocusListTableViewCell cellWithTableView:tableView identifier:identifier];
    cell.list = list;
    return cell;
}

/**
 *  UISearchController作为UITableView的tableHeaderView
 */
-(void)addSearchBar
{
    //创建UISearchController对象
    UISearchController *searchController = [[UISearchController alloc]initWithSearchResultsController:nil];
    //是否添加半透明覆盖层。为YES，搜索时，背景会变暗（背景变模糊）。默认为YES
    searchController.dimsBackgroundDuringPresentation = NO;
    //是否隐藏导航栏。为YES，搜索时，UINavigationBar会隐藏。默认为YES
    searchController.hidesNavigationBarDuringPresentation = YES;
    //NO表示UISearchController在present时，可以覆盖当前controller。默认为NO
    searchController.definesPresentationContext = NO;
    //搜索栏表头视图
    self.tableView.tableHeaderView = searchController.searchBar;
    
    [searchController.searchBar sizeToFit];
    searchController.searchResultsUpdater = self;
    
    searchController.searchBar.placeholder=@"请输入名称或者数字";
    searchController.searchBar.autocapitalizationType=UITextAutocapitalizationTypeNone;
    //    searchController.searchBar.showsCancelButton=YES;//显示取消按钮
    //自适应
    [searchController.searchBar sizeToFit];
    //    searchController.searchBar.frame = CGRectMake(0, 0, 0, 44);
    //    searchController.searchBar.prompt=@"请输入关键字";
    self.searchController = searchController;
}

- (void)updateSearchResultsForSearchController:(UISearchController *)searchController{
    NSString *searchString = self.searchController.searchBar.text;
    //NSPredicate 谓词
    NSPredicate *preicate = [NSPredicate predicateWithFormat:@"theme_name LIKE[c] %@", searchString];
    if (self.searchList!= nil) {
        [self.searchList removeAllObjects];
    }
    //过滤数据
    self.searchList= [NSMutableArray arrayWithArray:[self.list filteredArrayUsingPredicate:preicate]];
    //刷新表格
    [self.tableView reloadData];
}